Hey @afincato thanks for taking interest in the plugin. It is quite old and as @luxlogica pointed out, there are more native ways of doing this type of thing now. All the plugin really does is generate an object by recursively looping through pages.
As for the missing keys, it is possible the $page->toArray() method no longer includes them. You’d have to merge them in manually if that is the case (using page methods). In general, might be best to open issues like this on github itself.
Cheers, J